leedy2 wrote: I know many of you don't think of this as a fact but it has been proven for many years just no one put's to use and like to experiment with sound.
I politely beg to partially disagree, having used cow skin and mule skin in various combinations on all my congas and bongos.
Your personal experience regarding hand injury is highly useful for those hard hitters out there indeed though,
but one should not forget that technique, drum construction (e.g. bearing edge shape) and the tension of the skin might affect your hands in a positive or painful way too.
Besides, IMHO mule skin that is broken in thoroughly can have that velvet feel and resonate freely without being too hard on your hands and cowskin, on the other hand, can be quite tough too. All depending on thickness as well.